The frequently occurring components of essential oils beta elemene and R-limonene alter expression of dprE1 and clgR genes of Mycobacterium tuberculosis H37Ra.

In the past few years, there has been a significant increase in detection of drug resistant strains of Mycobacterium tuberculosis. Search for new antimycobacterial drugs brought natural sources with their chemical diversity in focus. Especially essential oils, produced by plants also for toxic effect, are reservoir of potentially antitubercular compounds. In the present work, we exposed M. tuberculosis H37Ra ATCC 25177 strain to some terpenes commonly occurring in essential oils. Gene expression profiling was used to explore possible influence of these compounds on stress sensing and envelope preserving function. Expression of two genes dprE1 involved in cell wall synthesis and clgR responsible for regulation of cell membrane preservation was investigated. We report that two out of five tested compounds: β-elemene and R-limonene alter expression of dprE1 and clgR genes. These findings indicate various mechanisms of action of essential oils compounds on M. tuberculosis. Especially the clgR expression seemed to be the perfect marker of stress sensing and envelope preserving systems status.